1. A method of reducing errors in data received from a data transmission network comprising the steps of:
(a) receiving from the data transmission network a variable length data frame having a received bit error rate (BER) and having a plurality of symbol sets, wherein each of said symbol sets demarks a respective field of said variable length data frame;
(b) storing said variable length data frame in a first buffer;
(c) providing a plurality of correlators, each of said plurality of correlators for calculating a respective Hamming distance;
(d) processing each of said symbol sets with at least one of said plurality of correlators to calculate respective Hamming-distances;
(e) providing a plurality of thresholds;
(f) calculating, using said respective Hamming-distances with a respective one of said plurality of thresholds, a plurality of threshold-compared Hamming-distance indicators;
(g) providing at least one multiple-correlation threshold;
(h) determining, using said plurality of threshold-compared Hamming-distance indicators with said at least one multiple-correlation threshold, a correlation decision indicator indicating the correlation of at least one of said plurality of symbol sets to said respective field of said variable length data frame;
(i) storing said correlation decision indicator in a second buffer; and
processing said variable length data frame from said first buffer in a forward error correction (FEC) processing module according to said correlation decision indicator from said second buffer, thereby providing received data having an improved bit error rate (BER).
2. The method of claim 1, wherein said variable length data frame includes a first symbol-set delimiting a beginning of a preamble field of said variable length data frames.
3. The method of claim 2, wherein said variable length data frame includes a second symbol-set delimiting an end parity-bytes field of said variable length data frames.
4. The method of claim 3, wherein said variable length data frame includes a third symbol-set delimiting an end of said variable length data frames.
5. The method of claim 4, wherein a first correlator of said plurality of correlators is based on said second symbol-set and a second of correlator of said plurality of correlators is based on said third symbol-set.
6. The method of claim 1 wherein at least one of said plurality of correlators uses a bit error rate (BER) threshold, said BER threshold depending on the BER of the processed variable length data frame.
7. The method of claim 1 wherein said step of determining further includes calculating a threshold-compared multiple-correlation indicator using at least one of said plurality of threshold-compared Hamming-distance indicators with said at least one multiple-correlation threshold, and then performing a logical-AND of said at least one of said plurality of threshold-compared Hamming-distance indicators and said threshold-compared multiple-correlation indicator to determine a correlation of at least one of said plurality of symbol sets to said respective field of said variable length data frame.
8. The method of claim 1 wherein said variable length data frame is an FEC-protected data frame.
9. The method of claim 1 wherein said step of determining further includes using said plurality of threshold-compared Hamming-distance indicators with a plurality of the given multiple-correlation thresholds, to determine a correlation of at least one of said plurality of symbol sets to said respective field of said variable length data frame.
10. The method of claim 1 further comprising the step of determining the length of said variable length data frame.
11. A method of reducing errors in data received from a data transmission network, comprising the steps of:
(a) receiving from the data transmission network a variable length data frame having a received bit error rate (BER) and having a plurality of symbol sets, wherein each of said symbol set demarks a respective field of said variable length data frame;
(b) storing said variable length data frame in a first buffer;
(c) providing at least one correlator for calculating a weighted-correlation indicator, wherein each said at least one correlator at least in part weights a Hamming distance based on bit-positions according to at least one given parameter set;
(d) processing each of said symbol sets with one of said at least one correlators to calculate respective weighted-correlation indicators;
(e) providing at least one threshold;
(f) calculating, using said weighted-correlation indicators with said at least one threshold, at least one threshold-compared Hamming-distance indicator;
(g) providing at least one weighted-correlation threshold;
(h) determining, using said at least one threshold-compared Hamming-distance indicator with said at least one weighted-correlation threshold, a correlation decision indicator indicating a correlation of at least one of said plurality of symbol sets to said respective field of said variable length data frame;
(i) storing said correlation decision indicator in a second buffer; and
(j) processing said variable length data frame from said first buffer in a forward error correction (FEC) processing module according to said correlation decision indicator from said second buffer, thereby providing received data having an improved bit error rate (BER).
12. The method of claim 11, wherein said variable length data frame includes a first symbol-set delimiting a beginning of a preamble field of said variable length data frames.
13. The method of claim 12, wherein said variable length data frame includes a second symbol-set delimiting an end a parity-bytes field of said variable length data frames.
14. The method of claim 13, wherein said variable length data frame includes a third symbol-set delimiting an end of said variable length data frames.
15. The method of claim 14, wherein a first correlator of said at least one correlator is based on said second symbol-set and a second correlator of said at least one correlator is based on said third symbol-set.
16. The method of claim 11, wherein at least one of said given parameter sets is based on one bit distances from a given correlated delimiter of said frame field.
17. The method of claim 11, wherein at least one of said given parameter sets is based on the BER of the processed variable length, data frame.
18. The method of claim 11 wherein said at least one correlator uses a bit error rate (BER) threshold, said BER threshold depending on the BER of the processed variable length data frame.
19. The method of claim 11, wherein said step of determining further includes calculating a threshold-compared multiple-correlation indicator using at least one of said threshold-compared Hamming-distance indicators with at least one said weighted-correlation threshold, and then performing a logical-AND of said at least one of said threshold-compared Hamming-distance indicators and said threshold-compared multiple-correlation indicator to determine the correlation of at least one of said plurality of symbol sets to said respective field of said variable length data frame.
20. The method of claim 11, wherein said data frame is an FEC-protected data frame.
21. The method of claim 11 further comprising the step of determining a length of said variable length data frame.
22. A system for receiving data from a data transmission network, comprising:
(a) a first buffer operationally connected to the data transmission network, said first buffer configured to store a variable length data frame received from the data transmission network, said variable length data frame having a received bit error rate (BER) and having a plurality of symbol sets, wherein each of said symbol sets demarks a respective field of said variable length data frame;
(b) a processing system including at least one processor, said processing system configured to:
(i) process each of said symbol sets with at least one of a plurality of correlators to calculate respective Hamming-distances;
(ii) calculate, using said respective Hamming-distances with one of a plurality of thresholds, a plurality of threshold-compared Hamming-distance indicators; and
(iii) determine, using said plurality of threshold-compared Hamming-distance indicators with at least one multiple-correlation threshold, a correlation decision indicator indicating a correlation of at least one of said plurality of symbol sets to said respective field of said variable length data frame;
(c) a second buffer configured to store said correlation decision indicator; and
(d) a forward error correction (FEC) processing module configured to process said variable length data frame from said first buffer according to said correlation decision indicator from said second buffer, thereby providing received data having an improved bit error rate (BER).
23. A system for receiving data from a data transmission network, comprising:
(a) a first buffer operationally connected to the data transmission network, said first buffer configured to store a variable length data frame received from the data transmission network, said variable length data frame having a received bit error rate (BER) and having a plurality of symbol sets, wherein each of said symbol sets demarks a respective field of said variable length data frame;
(b) a processing system including at least one processor, said processing system configured to:
(i) process each of said symbol sets with a correlator to calculate a respective weighted-correlation indicator, wherein said correlator is from a set of at least one correlators, and wherein each said correlator at least in part weights a Hamming distance based on bit-positions according to at least one given parameter set;
(ii) calculate, using said weighted-correlation indicators with at least one threshold, at least one threshold-compared Hamming-distance indicator; and
(iii) determine, using said at least one threshold-compared Hamming-distance indicator with at least one weighted-correlation threshold, a correlation decision indicator indicating the correlation of at least one of said plurality of symbol sets to said respective field of said variable length data frame;
(c) a second buffer configured to store said correlation decision indicator; and
(d) a forward error correction (FEC) processing module configured to process said variable length data frame from said first buffer according to said correlation decision indicator from said second buffer, thereby providing received data having an improved bit error rate (BER).
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1-14. (canceled)
15. A process for preparing an L-lysine salt of (R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid of Formula (Ia):
comprising the steps of:
a) hydrolyzing said compound of Formula (IIn):
wherein R6 is C1-C4 alkyl;
in the presence of a hydrolyzing-step base and a hydrolyzing-step solvent to form said (R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid; and
b) contacting said (R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid with L-lysine or a salt thereof, in the presence of a contacting-step solvent and H2O to form said L-lysine salt of (R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid.
16. A process for preparing an L-lysine salt of (R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid of Formula (Ia):
comprising the step of:
contacting the (R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid with L-lysine or a salt thereof, in the presence of a contacting-step solvent and H2O to form said L-lysine salt of (R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid.
17. The process according to claim 16, wherein said contacting-step solvent comprises acetonitrile, tetrahydrofuran, acetone, or ethyl acetate.
18. The process according to claim 16, wherein said contacting-step solvent comprises ethanol or isopropanol.
19. The process according to claim 16, wherein the molar ratio between said (R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid and L-lysine is about 1.0:1.0 to about 1.0:1.2.
20. The process according to claim 16, said process further comprising the step of isolating said L-lysine salt of (R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid.
21. The process according to claim 20, wherein after said isolating, said L-lysine salt of (R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid has a purity of about 97% or greater, and an enantiomeric excess of about 97% or greater.
22. A process for preparing (R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid of Formula (Ia):
comprising the step of:
hydrolyzing a compound of Formula (IIn):
wherein R6 is C1-C4 alkyl;
in the presence of a hydrolyzing-step base and a hydrolyzing-step solvent to form said (R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid.
23. The process according to claim 22, wherein R6 is CH2CH3.
24. The process according to claim 22, wherein said hydrolyzing-step base comprises sodium hydroxide.
25. The process according to claim 22, wherein said hydrolyzing-step solvent comprises dioxane, methanol, and water.
26. The process according to claim 22, wherein said hydrolyzing further comprises the step of isolating said (R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid.
27. The process according to claim 26, wherein after said isolating, said (R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid has an enantiomeric excess of about 97% or greater.
28-40. (canceled)
41. A process for preparing a composition comprising admixing a salt selected from:
(R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid L-lysine salt;
(R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid sodium salt;
(R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid sodium salt hydrate;
(R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid ethylenediamine salt hydrate;
(R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid 2-amino-2-hydroxymethyl-propane-1,3-diol salt;
(R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid L-arginine salt;
(R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid zinc salt;
(R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid calcium salt;
(R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid N-methylglucamine salt;
(R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid potassium salt; and
(R)-2-(9-chloro-7-(4-isopropoxy-3-(trifluoromethyl)benzyloxy)-2,3-dihydro-1H-pyrrolo1,2-aindol-1-yl)acetic acid magnesium salt;
and a pharmaceutically acceptable carrier.
42-56. (canceled)